The present invention relates generally to resonators, and more particularly to multiple conductor resonators exhibiting high Q, or quality factor.
One prior type of multiple conductor resonator is disclosed in Doty, Jr. U.S. Pat. No. 4,255,728. This type of resonator includes first and second conductors which are wound in helical fashion with the convolutions of one of the conductors being disposed between the convolutions of the other conductors to form a series of alternating first and second conductor turns. Each of the conductors includes first and second ends with the first and second ends of the first conductor comprising the terminals of the resonator and the first end of the second conductor being connected to the second end of the first conductor.
It has been found that the Q, or quality factor representing the efficiency of this type of resonator is adversely affected by the undesirable distributed capacitive coupling between a single turn of one conductor and another turn or convolution of that same conductor or the other conductor. This undesired capacitance, as well as other similar undesired capacitances hereinafter denoted "undesirable capacitance" or "undesirable capacitive coupling" is a high loss capacitance which reduces the efficiency or Q of the resonator.
Furthermore, when the resonator is operated at relatively high frequencies, the resonator exhibits skin effect which increases the ohmic resistance, and hence further decreases the Q of the resonator.
One way to decrease the undesirable interturn capacity is to substantially increase the pitch of the helical convolutions of the conductors to interpose gaps between turns of the conductors. By increasing the distance between turns, undesirable capacitance is lessened. However, this technique undesirably increases the size and weight of the resulting resonator.